Ballpoint refill units



Oct. 15, 1963 i R; R. REBO BALLPOINT REFILL UNITS Filed May 2, 1962 fiiqiki l2 INVENTOR.

RELNA R. REBO' FIG.9 BY

ATTORNEY United States Patent arenas? EALLPOHNT REFELL UNITS Reina R.Reba, (Irestwood, Mo, assignor to Ritepoint Pen and Pencil Company, St.Louis, Mo., a corporation of Mimonri Fiied May 2, 1962, Ser. No. $1,813Unions. (Cl. Mo 42.4)

This invention relates in general to disposable ink cartridges forballpoint pens and pencils and, more particularly, to an improved typeof a vented plug for a ballpoint refill unit. 1

The ink solutions presently used in refill units for calpoint pens andballpoint pencils have a very low viscosity and, therefore, extreme caremust be taken in the design of the refill unit to prevent any of theliquid ink from unauthorizedly leaking out of the refill. This ink isusually a non-water soluble material and when accidentally spilled onclothing or furniture will cause a permanent stain that cannot beremoved by any known bleach or cleaning agent.

It is, of course, necessary that each of these refill units be vented tothe atmosphere in order that the ink within the refill tube will flowauthorizedly out of a tubular channel formed within the writing point.In order to accomplish a continued authorized flow and yet prevent aspillage of the ink, the refill units presently existing have beenformed with an open-ended long narrow stem which contains the writingink. This ink usually has a sufliciently high surface tension so that itis maintained within the tubular container by capillary action. However,the amount of ink in the refill container is limited because thediameter of the container must be kept within a certain size range sothat this capillary action will not be eliminated.

There have been some attempts to design large refill units of theso-called giant refill type, which contains a larger supply of ink andis provided with a vented cap at the open end. This cap must be designedwithin a high tolerance and a proper size air-venting aperture so'thatthe liquid ink within the refill unit will flow through the writingpoint. If the venting aperture is too small, the liquid ink will notflow, and if the venting aperture is too large there is a danger of theink leakage. For this reason, these refill caps have not beenparticularly effective.

There have been other attempts to prevent leakage in large diameterballpoint refills such as the use of the close-running ball. in thiscase, the ball will fall to the lower end of the tube when the ink tubeis turned upside down so that its open end is pointed downwardly andthus acts as a closure valve to prevent the unauthorized escape of theliquid ink. Other attempts to prevent the unauthorized escape of theliquid ink resides in the use of convoluted ink tubes which have agreater length than the length of the normal pen or pencil barrel inwhich the tube is to be inserted. A number of attempts have also residedin the employment of plugs with internal baffling and with refillmentshaving mechanical spring-type valve arrangements inside the tube for thecontrol of leakage. However, all of these attempts have proved to beeither commercially unfeasible or ineffective.

It is, therefore, the primary object of the present invention to providea ballpoint refill unit which can be constructed with a large diametralsize and does not require the use of an end cap.

It is another object of the present invention to provide a ballpointrefill unit of the type stated which is designed to contain a largequantity of ink solution.

It is a further object of the present invention to provide a ballpointrefill unit of the type stated which is properly vented so that the inksolution will adequately llow "ice (1-: through the writing point andyet will not leak through the open end of the refill unit.

It is an additional object of the present invention to provide aballpoint refill unit of the type stated which has a long life and iseconomical to manufacture.

It is also an object of the present invention to provide a ballpointrefill unit of the type stated which can be manufactured in varioussizes and shapes to fit almost all ballpoint pens and pencils.

With the above and other objects in view, my invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims.

In the accompanying drawings (one sheet) FIG. 1 is a side elevationalview of a ballpoint refill unit constructed in accordance with andembodying the present invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIGS. 3, 4, 5, and 6 are sectional views taken along lines 3-3, 4-4, 55,and 66, respectively, of FIG. 2;

FIG. 7 is a perspective view of a vented plug forming part of thepresent invention;

FIG. 8 is a perspective view of a vented plug forming part of thepresent invention, taken at a different angle; and

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8.

Referring now in more detail and by reference characters to the drawing,which illustrates a preferred embodiment of the present invention, Adesignates a ballpoint refill unit comprising a tubular cartridge 1having a diametrally reduced forward portion 2, reference being made toFIG. 2, and which is adapted for accommodating a conventional ballpointinsert 3. The diametrally reduced portion 2 is formed of a relativelyshort length which is just sufilcient to extend through the restrictedspace at the tapered writing point of a conventional ballpoint pen orpencil (not shown). The tubular cartridge 1 is internally sized to forma substantially cylindrical reservoir or chamber 4 for containing asolution of writing ink which is preferably though not necessarilyprovided at its rearward end 5 with a closure plug 6 having a shallowaxial vent-slot 7, as shown in FIG. 1, if desired.

Disposed within the reservoir 4 near the open rearward end 5, is aflow-control plug 8 comprising a main cylindrical body 9 having endwalls 1t 11. The length of the cylindrical body 9 is substantiallysmall, relative to the overall length of the tubular cartridge l and issized to fit snugly within the chamber 4, substantially as shown in PEG.2. integrally formed with and extending rearwardly of the cylindricalbody 9 is a coaxial hollow tube 12 which is centrally bored, andcommunicates with, an axial duct 13 formed centrally of the cylindricalbody 9. The co axial tube 12 extends rearwardly from and is formed onthe exact diametral center of the end wall 11. Extending forwardly ofthe cylindrical body 9 is a hollow tube 14 which is parallel to andeccentric with respect to the tube 12 overlapping the latter within thecylindrical body 9 in the formation of an offset opening 15 between thetubes 12, 14. By reference to FIG. 2, it can be seen that the tube 14has a greatre length than the length of the tube 12. Furthermore, thetube 14 is positioned on the cylindrical body 9 in such manner that oneportion of the peripheral wall of the tube 14 is axially tangent with aportion of the peripheral wall of the cylindrical body 9 so that thetube 14 lies flush, along such axial line of tangency, against a portionof the inner peripheral surface of the chamber 4.

It has been found, in connection with the present invention, that theaperture formed by the intersection of the internal ends of tubes 12,14, is sufficient to provide an air vent which is required for properink flow and yet will maintain capillary action within the tube chamber4 to prevent any authorized or undesired reverse flow of the ink throughthe tube.

In use, the plug 8 is inserted within the tubular cartridge 1 from theopen end thereof after the cartridge 1 has been filled with a sufficientquantity of heavy viscosity ink of the type commonly used in ballpointpens. The plug 8 is disposed within the chamber 4 until the rearward endof the coaxial tube 12 is recessed slightly from the open end 5 of thetubular cartridge 1. If the cartridge is upended the ink will not flowpast the tube 14. It has been found by quality-control tests that ifthese tubular cartridges 1 are suspended so that the rearward end 5 ispointed downwardly, no ink leakage will occur.

It should be understood that changes and modifications in the form,construction, arrangement, and combination of the several parts of theballpoint refill units may be made and substituted for those hereinshown and described without departing from the nature and principle ofmy invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A ballpoint refill unit comprising a tubular member open at one end,writing means disposed within the other end of said tubular member, acylindrical plug disposed completely within said tubular member so thatits outer wall snugly engages the interior wall of the tubular member insealingwise contact, said plug having a central axial bore extending forapproximately half of its axial length, said plug also having adiametrally offset axial bore for the remainder of its axial length andcommunicating with said central axial bore, a first tubular memberconnected to one end of said plug and extending outwardly therefrom,said first tubular member communicating with said central axial bore,and a second tubular member connected to the other end of said plug andextending outwardly therefrom, said second tubular member communicatingwith said diametrally offset axial bore.

2. A ballpoint refill unit comprising a tubular member open at one end,writing means disposed within the other end of said tubular member, acylindrical plug disposed completely within said tubular member so thatits outer wall snugly engages the interior wall of the tubular member insealingwise contact, said plug having a central axial bore extending forapproximately half of its axial length, said plug also having adiametrally offset axial bore for the remainder of its axial length andcommunicating with said central axial bore, a first tubular memberconnected to one end of said plug and extending outwardly therefrom,said first tubular member communicating with said central axial bore,and a second tubular member connected to the other end of said plug andextending outwardly therefrom, said second tubular member communieatingwith said diametrally olfset axial bore, said second tubular memberbeing connected to said plug in such manner that a portion of itsperipheral surface is flush with 4 the peripheral surface of said plugand engages the interior wall of said tubular member.

3. A vented plug for use in a ballpoint refill unit, said plugcomprising a solid cylindrical member having a central bore extending aportion of its length, said member having a diametrally offset borewhich is offset from the central bore and extends the remainder of itslength, said central bore communcating with said diametrally oifsetbore, and a tubular member connected to one end of said cylindricalmember and extending outwardly therefrom, said tubular membercommunicating with said central bore.

4. A vented plug for use in a ballpoint refill unit, said plugcomprising a solid cylindrical member having a central bore extending aportion of its length, said member having a diametrally offset borewhich is offset from the central bore and extends the remainder of itslength, said central bore communicating with said diametrally offsetbore, a first tubular member connected to one end of said cylindricalmember and extending outwardly therefrom, said first tubular membercommunicating with said central bore, and a second tubular memberconnected to the other end of said solid cylindrical member andextending outwardly therefrom, said second tubular member communicatingwith said diametrally offset bore.

5. A vented plug for use in a ballpoint refill unit, said plugcomprising a solid cylindrical member having a central bore extending aportion of its length, said member having a diametrally offset borewhich is offset from the central bore and extends the remainder of itslength, said central bore intersecting with said diametrally offset boreat a common internal chamber having a diametral size which is smallerthan the combined diametral sizes of the central bore and diametrallyoffset bore, a first tubular member connected to one end of saidcylindrical member and extending outwardly therefrom, said first tubularmember communicating with said central bore, and a second tubular memberconnected to the other end of said solid cylindrical member andextending outwardly therefrom, said second tubular member communicatingwith said diametrally otfset bore, said second tubular member beingconnected to said solid cylindrical member in such manner that a portionof its peripheral surface lies flush with the peripheral surface ofsaid'solid cylindrical member.

References Qited in the file of this patent UNITED STATES PATENTS2,505,211 Schiessel Apr. 25, 1950 2,521,285 Dearman Sept. 5, 1950FOREEGN PATENTS 943,341 France Oct. 4, 1948 803,094 Germany Feb. 26,1951 1,030,853 France Mar. 18, 1953 1,133,813 France Nov. 26, 1956

3. A VENTED PLUG FOR USE IN A BALLPOINT REFILL UNIT, SAID PLUGCOMPRISING A SOLID CYLINDRICAL MEMBER HAVING A CENTRAL BORE EXTENDING APORTION OF ITS LENGTH, SAID MEMBER HAVING A DIAMETRICALLY OFFSET BOREWHICH IS OFFSET FROM THE CENTRAL BORE AND EXTENDS THE REMAINER OF ITSLENGTH, SAID CENTRAL BORE COMMUNICATING WITH SAID DIAMETRICALLY OFFSET